samedi 12 avril 2014

April 12, 2014 underwent elective correction orbit of the International Space Station.

According to calculations by the ballistic and navigation support Mission Control Center FSUE TsNIIMash today in 19 hours 16 minutes Moscow time included engines cargo spacecraft Progress M-21M. Ship's engines worked 812 seconds. As a result, ISS received a velocity increment of 1.84 m/s. The average height of the station's orbit increased by 3.4 km and reached 417.55 km.

ISS reboost by Progress M cargo spacecraft

According to the service ballistic and navigation support MCC after the ISS orbit maneuver parameters were as follows:

On March 20, 2014, Dassault Aviation organized a formation flight of the nEUROn unmanned combat air vehicle (UCAV) with a Rafale fighter and a Falcon 7X business jet. This was the first time in the world that a combat drone flew in formation with other aircraft. The entire operation lasted 1 hour and 50 minutes and took the patrol out over the Mediterranean to a range of several hundred kilometers.

The Patrol: nEUROn, Rafale, Falcon 7X

According to Eric Trappier, Chairman and CEO of Dassault Aviation, “This achievement clearly reflects our expertise in state-of-the-art technologies. Our skills in both military and civil aviation mutually enrich each other, enabling us to design exceptional airplanes suited for both the armed forces and Falcon business jet operators.”

The Patrol: nEUROn, Rafale, Falcon 7X - Dassault Aviation

Organizing a formation flight like this was a daunting challenge: for each maneuver in the planned sequence, aircraft from different holding points and with very different characteristics had to fly alongside each other in a confined space.

The Patrol: nEUROn, Rafale, Falcon 7X

An additional challenge was being able to control a pilotless aircraft flying near four other aircraft, all manned (Rafale, Falcon 7X and two chase aircraft for photography). Engineers had to plan ahead to take into account the risk of interference, including aerodynamic turbulence between the aircraft, not to mention electromagnetic interference (EMI) with communications between the nEUROn drone and its ground control station.

About nEUROn

nEUROn is a European program for an unmanned combat air vehicle (UCAV) technology demonstrator, conducted by Dassault Aviation as prime contractor under the authority of French defense procurement agency DGA. It heralds tomorrow’s defense programs, since it federates expertise from across Europe (France, Italy, Sweden, Spain, Greece and Switzerland). The nEUROn program is designed to validate the development of complex technologies representing all mission systems: high-level flight control and stealth, launching real air-to-ground weapons from an internal bay, integration in the C4I environment, innovative industrial collaboration processes, etc. The demonstrator made its first flight on December 1, 2012, paving the way for a two-year test program. Since then, the nEUROn drone has carried out several dozen test flights.

About Dassault Aviation

With over 8,000 military and civil aircraft delivered to 83 countries over the last 60 years, logging some 28 million hours in flight, Dassault Aviation has built up expertise recognized worldwide in the design, development, sale and support of all types of aircraft, ranging from the Rafale fighter to the high-end Falcon family of business jets and military drones. Dassault Aviation posted sales of 4.59 billion euros in 2013, and has nearly 11,600 employees.

vendredi 11 avril 2014

This year at the world's largest industrial fair, the Hannover Messe, CERN and the European Space Agency (ESA) have teamed up to present their technologies. Some of the technologies developed by CERN could find applications in space.

In the planned upgrades of detectors on the Large Hadron Collider (LHC), electronics will come under intense radiation from high-energy particle beams. So electronics engineers at CERN have developed a power converter that can take a radiation dose of up to 7 million Gray and is not disturbed by single particle hits. Because power distribution is also an issue on spacecraft, the engineers – and CERN’s Knowledge Transfer group – believe that the converter could be useful in space.

Then there’s the problem of thermal management. Devices called collimators narrow the beams in particle accelerators. On the LHC they suffer intense heat, acting as "brakes" to strip particles from the edges of spreading beams. With the higher energies and intensities planned for the upgraded LHC, researchers are looking to improve on the carbon-based composite materials currently in use for collimators.

"The material [for the collimator] needs to be robust, conduct heat away quickly, have high geometrical stability and conduct electricity so as not to adversely influence the beam," says Alessandro Bertarelli, an aerospace engineer turned beam expert at CERN.

Image above: CERN and the European Space Agency share a stand to present their technologies at Hannover Messe, the world’s biggest industrial fair (Image: rheinland relations).

The possible solution: a molybdenum-carbide–graphite composite. "It has better electrical properties than the current collimators," says Bertarelli. "And its thermal conductivity is four times better – probably a world record for an engineered material." The composite is also quite light and very stable up to high temperatures – it could find a use on aircraft or in the harsh environment of space.

Another technology that could come in handy in space is related to surfaces in ultra-high vacuum. Particle beams have electric fields that can knock electrons from metallic surfaces around them. These electrons knock out even more electrons and so on. The process, called beam-induced multipactoring, forms an unwanted electron cloud that interferes with the beam.

Rough surfaces or coatings with particular chemical composition can mitigate this effect by reducing the number of secondary electrons produced. So engineers sometimes use special coatings – amorphous carbon, for example.

But mechanically rough surfaces can have drawbacks. "They are likely to increase the radiofrequency losses in microwave applications," says beam physicist Fritz Caspers. "So [a team at CERN is] looking at surfaces which are mechanically very smooth."

Instead of a surface that is rough in a mechanical way the CERN team invented a surface that is rough in a magnetic way. Tiny permanent magnets of alternating polarity applied just underneath the surface of high-frequency-carrying structures can trap secondary electrons. The technology reduces the secondary electron yield without the drawbacks of a rough surface.

Magnetic surface roughness could be used in particle physics, powering structures such as klystrons that use high frequencies. Spacecraft also suffer from efficiency losses due to stray electrons, and rough magnetic surfaces could be a basis of discussion for loss-free power transport in space.

The concept of magnetic surface roughness could one day find applications in radiofrequency systems on board satellites.

CERN and ESA recently signed a cooperation agreement. With so much overlap between technology for aerospace and particle physics, it's off to a good start.

CERN, the European Organization for Nuclear Research, is one of the world’s largest and most respected centres for scientific research. Its business is fundamental physics, finding out what the Universe is made of and how it works. At CERN, the world’s largest and most complex scientific instruments are used to study the basic constituents of matter — the fundamental particles. By studying what happens when these particles collide, physicists learn about the laws of Nature.

The instruments used at CERN are particle accelerators and detectors. Accelerators boost beams of particles to high energies before they are made to collide with each other or with stationary targets. Detectors observe and record the results of these collisions.

Founded in 1954, the CERN Laboratory sits astride the Franco–Swiss border near Geneva. It was one of Europe’s first joint ventures and now has 20 Member States.

jeudi 10 avril 2014

A United Launch Alliance Atlas 5 rocket, designated AV-045, launch a classified spacecraft payload for the U.S. National Reconnaissance Office. The rocket fly in the 541 vehicle configuration with a five-meter fairing, four solid rocket boosters and a single-engine Centaur upper stage.

Launch of NROL-67 Top Secret Payload on Atlas V541 Rocket

An American Atlas V541 rocket successfully blasted off from Cape Canaveral's Space Launch Complex 41, Cape Canaveral Air Force Station today, April 10th 2014 at 17:45 UTC carrying a top secret payload for the National Reconnaissance Office simply known as 'NROL-67'. This was the 45th launch of an Atlas V rocket since 2002.

Titan, Europa, Io and Phobos are just a few members of our solar system's pantheon of moons. Are there are other moons out there, orbiting planets beyond our sun?

NASA-funded researchers have spotted the first signs of an "exomoon," and though they say it's impossible to confirm its presence, the finding is a tantalizing first step toward locating others. The discovery was made by watching a chance encounter of objects in our galaxy, which can be witnessed only once.

"We won't have a chance to observe the exomoon candidate again," said David Bennett of the University of Notre Dame, Ind., lead author of a new paper on the findings appearing in the Astrophysical Journal. "But we can expect more unexpected finds like this."

The international study is led by the joint Japan-New Zealand-American Microlensing Observations in Astrophysics (MOA) and the Probing Lensing Anomalies NETwork (PLANET) programs, using telescopes in New Zealand and Tasmania. Their technique, called gravitational microlensing, takes advantage of chance alignments between stars. When a foreground star passes between us and a more distant star, the closer star can act like a magnifying glass to focus and brighten the light of the more distant one. These brightening events usually last about a month.

If the foreground star -- or what astronomers refer to as the lens -- has a planet circling around it, the planet will act as a second lens to brighten or dim the light even more. By carefully scrutinizing these brightening events, astronomers can figure out the mass of the foreground star relative to its planet.

In some cases, however, the foreground object could be a free-floating planet, not a star. Researchers might then be able to measure the mass of the planet relative to its orbiting companion: a moon. While astronomers are actively looking for exomoons -- for example, using data from NASA's Kepler mission - so far, they have not found any.

In the new study, the nature of the foreground, lensing object is not clear. The ratio of the larger body to its smaller companion is 2,000 to 1. That means the pair could be either a small, faint star circled by a planet about 18 times the mass of Earth -- or a planet more massive than Jupiter coupled with a moon weighing less than Earth.

The problem is that astronomers have no way of telling which of these two scenarios is correct.

"One possibility is for the lensing system to be a planet and its moon, which if true, would be a spectacular discovery of a totally new type of system," said Wes Traub, the chief scientist for NASA's Exoplanet Exploration Program office at NASA's Jet Propulsion Laboratory, Pasadena, Calif., who was not involved in the study. "The researchers' models point to the moon solution, but if you simply look at what scenario is more likely in nature, the star solution wins."

The answer to the mystery lies in learning the distance to the circling duo. A lower-mass pair closer to Earth will produce the same kind of brightening event as a more massive pair located farther away. But once a brightening event is over, it's very difficult to take additional measurements of the lensing system and determine the distance. The true identity of the exomoon candidate and its companion, a system dubbed MOA-2011-BLG-262, will remain unknown.

In the future, however, it may be possible to obtain these distance measurements during lensing events. For example, NASA's Spitzer and Kepler space telescopes, both of which revolve around the sun in Earth-trailing orbits, are far enough away from Earth to be great tools for the parallax-distance technique.

Image above: Microlensing Observations in Astrophysics (MOA) in New Zealand has been monitoring 2.2° of sky since 2006.

The basic principle of parallax can be explained by holding your finger out, closing one eye after the other, and watching your finger jump back and forth. A distant star, when viewed from two telescopes spaced really far apart, will also appear to move. When combined with a lensing event, the parallax effect alters how a telescope will view the resulting magnification of starlight. Though the technique works best using one telescope on Earth and one in space, such as Spitzer or Kepler, two ground-based telescopes on different sides of our planet can also be used.

Meanwhile, surveys like MOA and the Polish Optical Gravitational Experiment Lensing Experiment, or OGLE, are turning up more and more planets. These microlensing surveys have discovered dozens of exoplanets so far, in orbit around stars and free-floating. A previous NASA-funded study, also led by the MOA team, was the first to find strong evidence for planets the size of Jupiter roaming alone in space, presumably after they were kicked out of forming planetary systems. (See http://www.jpl.nasa.gov/news/news.php?release=2011-147).

The new exomoon candidate, if real, would orbit one such free-floating planet. The planet may have been ejected from the dusty confines of a young planetary system, while keeping its companion moon in tow.

The ground-based telescopes used in the study are the Mount John University Observatory in New Zealand and the Mount Canopus Observatory in Tasmania.

Additional observations were obtained with the W.M. Keck Observatory in Mauna Kea, Hawaii; European Southern Observatory's VISTA telescope in Chile; the Optical Gravitational Lens Experiment (OGLE) using the Las Campanas Observatory in Chile; the Microlensing Follow-Up Network (MicroFUN) using the Cerro Tololo Interamerican Observatory in Chile; and the Robonet Collaboration using the Faulkes Telescope South in Siding Spring, Australia.

Using NASA's Hubble Space Telescope, astronomers now can precisely measure the distance of stars up to 10,000 light-years away -- 10 times farther than previously possible.

Astronomers have developed yet another novel way to use the 24-year-old space telescope by employing a technique called spatial scanning, which dramatically improves Hubble's accuracy for making angular measurements. The technique, when applied to the age-old method for gauging distances called astronomical parallax, extends Hubble's tape measure 10 times farther into space.

Image above: By applying a technique called spatial scanning to an age-old method for gauging distances called astronomical parallax, scientists now can use NASA’s Hubble Space Telescope to make precision distance measurements 10 times farther into our galaxy than previously possible. Image Credit: NASA/ESA, A.Feild/STScI.

"This new capability is expected to yield new insight into the nature of dark energy, a mysterious component of space that is pushing the universe apart at an ever-faster rate," said Noble laureate Adam Riess of the Space Telescope Science Institute (STScI) in Baltimore, Md.

Parallax, a trigonometric technique, is the most reliable method for making astronomical distance measurements, and a practice long employed by land surveyors here on Earth. The diameter of Earth's orbit is the base of a triangle and the star is the apex where the triangle's sides meet. The lengths of the sides are calculated by accurately measuring the three angles of the resulting triangle.

Astronomical parallax works reliably well for stars within a few hundred light-years of Earth. For example, measurements of the distance to Alpha Centauri, the star system closest to our sun, vary only by one arc second. This variance in distance is equal to the apparent width of a dime seen from two miles away.

Stars farther out have much smaller angles of apparent back-and-forth motion that are extremely difficult to measure. Astronomers have pushed to extend the parallax yardstick ever deeper into our galaxy by measuring smaller angles more accurately.

This new long-range precision was proven when scientists successfully used Hubble to measure the distance of a special class of bright stars called Cepheid variables, approximately 7,500 light-years away in the northern constellation Auriga. The technique worked so well, they are now using Hubble to measure the distances of other far-flung Cepheids.

Such measurements will be used to provide firmer footing for the so-called cosmic "distance ladder." This ladder's "bottom rung" is built on measurements to Cepheid variable stars that, because of their known brightness, have been used for more than a century to gauge the size of the observable universe. They are the first step in calibrating far more distant extra-galactic milepost markers such as Type Ia supernovae.

Hubble Space Telescope. Image Credit: NASA/ESA

Riess and the Johns Hopkins University in Baltimore, Md., in collaboration with Stefano Casertano of STScI, developed a technique to use Hubble to make measurements as small as five-billionths of a degree.

To make a distance measurement, two exposures of the target Cepheid star were taken six months apart, when Earth was on opposite sides of the sun. A very subtle shift in the star's position was measured to an accuracy of 1/1,000 the width of a single image pixel in Hubble's Wide Field Camera 3, which has 16.8 megapixels total. A third exposure was taken after another six months to allow for the team to subtract the effects of the subtle space motion of stars, with additional exposures used to remove other sources of error.

Riess shares the 2011 Nobel Prize in Physics with another team for his leadership in the 1998 discovery the expansion rate of the universe is accelerating -- a phenomenon widely attributed to a mysterious, unexplained dark energy filling the universe. This new high-precision distance measurement technique is enabling Riess to gauge just how much the universe is stretching. His goal is to refine estimates of the universe's expansion rate to the point where dark energy can be better characterized.

The Hubble Space Telescope is a project of international cooperation between NASA and the European Space Agency. NASA's Goddard Space Flight Center in Greenbelt, Md., manages the telescope. STScI conducts Hubble science operations. STScI is operated for NASA by the Association of Universities for Research in Astronomy, Inc., in Washington.

Supernovas are the spectacular ends to the lives of many massive stars. These explosions, which occur on average twice a century in the Milky Way, can produce enormous amounts of energy and be as bright as an entire galaxy. These events are also important because the remains of the shattered star are hurled into space. As this debris field – called a supernova remnant – expands, it carries the material it encounters along with it.

Astronomers have identified a supernova remnant that has several unusual properties. First, they found that this supernova remnant – known as G352.7-0.1 (or, G352 for short) – has swept up a remarkable amount of material, equivalent to about 45 times the mass of the Sun.

Another atypical trait of G352 is that it has a very different shape in radio data compared to that in X-rays. Most of the radio emission is shaped like an ellipse, contrasting with the X-ray emission that fills in the center of the radio ellipse. This is seen in a new composite image of G352 that contains X-rays from NASA’s Chandra X-ray Observatory in blue and radio data from the National Science Foundation's Karl G. Jansky Very Large Array in pink. These data have also been combined with infrared data from the Spitzer Space Telescope in orange, and optical data from the Digitized Sky Survey in white. (The infrared emission to the upper left and lower right are not directly related to the supernova remnant.)

A recent study suggests that, surprisingly, the X-ray emission in G352 is dominated by the hotter (about 30 million degrees Celsius) debris from the explosion, rather than cooler (about 2 million degrees) emission from surrounding material that has been swept up by the expanding shock wave. This is curious because astronomers estimate that G352 exploded about 2,200 years ago, and supernova remnants of this age usually produce X-rays that are dominated by swept-up material. Scientists are still trying to come up with an explanation for this behavior.

Chandra X-ray Observatory

Although it does not produce a lot of X-ray emission, the amount of material – the aforementioned 45 times the Sun’s mass – swept up by G352 is remarkably high for a supernova remnant located in our Galaxy. This may indicate that a special type of evolution has occurred, in which the massive star that exploded to create G352 interacted with an extraordinary amount of dense surrounding material.

Astronomers also conducted a search for a neutron star that may have been produced by the supernova explosion. They did not find any hints of a neutron star in G352, another astronomical puzzle involved with this system. One possibility is simply that the neutron star is too faint to be detected or that the supernova created a black hole instead.

G352 is found about 24,000 light years from Earth in the Milky Way galaxy. A paper describing these enigmatic results was published in the February 20th, 2014 issue of The Astrophysical Journal, and is available online. The first author of this paper is Thomas Pannuti from Morehead State University in Morehead, Kentucky, with co-authors Oleg Kargaltsev (George Washington University), Jared Napier (Morehead State), and Derek Brehm (George Washington).

Beautiful streamlined islands and narrow gorges were carved by fast-flowing water pounding through a small, plateau region near the southeastern margin of the vast Vallis Marineris canyon system.

Images captured on 7 December 2013 by ESA’s Mars Express show the central portion of Osuga Valles, which has a total length of 164 km. It is some 170 km south of Eos Chaos, which lies in the far eastern section of Valles Marineris.

Osuga Valles in context

Osuga Valles is an outflow channel that emanates from a region of chaotic terrain at the edge of Eos Chaos to the west (top in the main images). Such landscape is dominated by randomly oriented and heavily eroded blocks of terrain. Another example is seen at the bottom of this scene, filling the 2.5 km-deep depression into which Osuga Valles empties.

Osuga Valles topography

Catastrophic flooding is thought to have created the heavily eroded Osuga Valles and the features within it. Streamlines around the islands in the valley indicate that the direction of flow was towards the northeast (bottom right in the main colour, topographic and 3D images shown here) and sets of parallel, narrow grooves on the floor of the channel suggest that the water was fast flowing.

Differences in elevation within the feature, along with the presence and cross-cutting relationships of channels carved onto the islands, suggest that Osuga Valles experienced several episodes of flooding. The perspective view, which is oriented with the direction of the water flow towards the top of the image, shows the details of the grooved valley floor and the channels carved into the islands more clearly.

Perspective view of Osuga Valles

Close to the northern-most (far right) part of the channel in the main images, two large irregular-shaped blocks appear to have broken away from the surrounding terrain, but do not seem to have experienced as much erosion as the rounded islands.

Osuga Valles in 3D

The floodwater eventually emptied into the deep depression of chaotic terrain at the bottom of the main images, but it is not yet known whether the water drained away into the subsurface or formed a temporary lake.

mercredi 9 avril 2014

April 10, 2014 at 01:14 Moscow time (MSK) logistics vehicle (THC) Progress M-23M docked with the docking module Pirs of the Russian segment of the International Space Station (ISS).

New Space Station Supply Ship Arrives At The Orbital Outpost

Automatic docking operations were conducted under the supervision of the Russian members of the ISS crew and Mission Control Center specialists FSUE TsNIIMash.

Just six hours after its launch from the Baikonur Cosmodrome in Kazakhstan April 9, the unpiloted Russian ISS Progress 55 cargo craft arrived at the International Space Station following a same-day journey to deliver almost three tons of food, fuel and supplies to the six-man Expedition 39 crew.

Excluding fuel to maintain orbit, equipment for retrofitting station , food, water and air for astronauts pilings with scientific equipment for experiments, space "truck" special cargo delivered into orbit within the " Ribbon of St. George." It is planned that on April 24, Russian cosmonauts aboard the ISS will join the activities to mark the celebration of the 69th anniversary of the Victory in the Great Patriotic War.

An express cargo delivery is on its way to the International Space Station. Nearly 3 tons of food, fuel and gear to replenish Expedition 39 launched aboard an ISS Progress 55 resupply craft at 11:26 a.m. EDT from the Baikonur Cosmodrome in Kazakhstan.

New Space Station Supply Ship Launches from Kazakhstan

The Russian space freighter will orbit Earth just four times before docking to the Pirs docking compartment at 5:20 p.m.

The 55P will occupy the same docking port left open when another Progress, the 54P, departed Monday morning filled with trash after a two-month stay. It is orbiting Earth for several days of orbital engineering tests before finally reentering the atmosphere for a fiery disposal.

There will be four vehicles docked at the orbital laboratory after the 55P arrives. Currently, there are two Soyuz vehicles and an ISS Progress 53 parked at the station. The Soyuz TMA-11M is docked to the Rassvet docking compartment and the Soyuz TMA-12M is docked to the Poisk docking compartment. The 53P space freighter is docked to the aft end of the Zvezda service module.

Image above: A Progress resupply ship arrives at the International Space Station Feb. 5, 2013.

A fifth cargo vehicle is being readied for its mission to the space station next week. SpaceX will launch its third Dragon commercial cargo craft aboard a Falcon 9 rocket Monday April 14 at 4:58 p.m. from Cape Canaveral Air Force Station in Florida.

When the Dragon arrives for its rendezvous with the station two days later it will be captured by the station’s robotic arm, Canadarm2, for a berthing to the Harmony node. The Dragon is the first space station resupply vehicle with return capability, safely delivering science research for analysis and gear for inspection, for retrieval off the coast of California.

Orbital Sciences’ Cygnus commercial resupply ship aboard an Antares rocket is lined up to follow the SpaceX Dragon when it leaves in mid-May. Scheduled for a May 6 launch, its approach and rendezvous profile will be similar to the Dragon. It will also be captured by the Canadarm2 for a berthing to Harmony. However, after it’s unberthing and release from the station’s robotic arm it will deorbit over the Pacific Ocean for a destructive reentry just like a Progress spacecraft.

The planetary nebula Abell 33 captured using ESO's Very Large Telescope

Astronomers using ESO’s Very Large Telescope in Chile have captured this eye-catching image of planetary nebula PN A66 33 — usually known as Abell 33. Created when an aging star blew off its outer layers, this beautiful blue bubble is, by chance, aligned with a foreground star, and bears an uncanny resemblance to a diamond engagement ring. This cosmic gem is unusually symmetric, appearing to be almost circular on the sky.

The planetary nebula Abell 33 in the constellation of Hydra

Most stars with masses similar to that of our Sun will end their lives as white dwarfs — small, very dense, and hot bodies that slowly cool down over billions of years. On the way to this final phase of their lives the stars throw their atmospheres out into the space and create planetary nebulae, colourful glowing clouds of gas surrounding the small, bright stellar relics.

Wide-field view of the sky around Abell 33

This image, captured by ESO’s Very Large Telescope (VLT), shows the remarkably round planetary nebula Abell 33, located roughly 2500 light-years from Earth. Being perfectly round is uncommon for these objects — usually something disturbs the symmetry and causes the planetary nebula to display irregular shapes [1].

Zooming in on the planetary nebula Abell 33

The strikingly bright star located along the rim of the nebula creates a beautiful illusion in this VLT image. This is just a chance alignment — the star, named HD 83535, lies in the foreground of the nebula, between Earth and Abell 33, in just the right place to make this view even more beautiful. Together, HD 83535 and Abell 33 create a sparkling diamond ring.

The remnant of Abell 33’s progenitor star, on its way to becoming a white dwarf, can be seen just slightly off-centre inside the nebula, visible as a tiny white pearl. It is still bright — more luminous than our own Sun — and emits enough ultraviolet radiation to make the bubble of expelled atmosphere glow [2].

Panning across the planetary nebula Abell 33

Abell 33 is just one of the 86 objects included in astronomer George Abell's 1966 Abell Catalogue of Planetary Nebulae. Abell also scoured the skies for galaxy clusters, compiling the Abell Catalogue of over 4000 of these clusters in both the northern and southern hemispheres of the sky.

This image uses data from the FOcal Reducer and low dispersion Spectrograph (FORS) instrument attached to the VLT, which were acquired as part of the ESO Cosmic Gems programme [3].

Notes:

[1] For example, the way the star spins, or if the central star is one component of a double or multiple star system.

[2] In this very sharp image the central star appears to be double. Whether this is a real association or just a chance alignment is not known.

[3] The ESO Cosmic Gems programme is an outreach initiative to produce images of interesting, intriguing or visually attractive objects using ESO telescopes, for the purposes of education and public outreach. The programme makes use of telescope time that cannot be used for science observations. All data collected may also be suitable for scientific purposes, and are made available to astronomers through ESO’s science archive.

More information:

ESO is the foremost intergovernmental astronomy organisation in Europe and the world’s most productive ground-based astronomical observatory by far. It is supported by 15 countries: Austria, Belgium, Brazil, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Portugal, Spain, Sweden, Switzerland and the United Kingdom. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope, the world’s most advanced visible-light astronomical observatory and two survey telescopes. VISTA works in the infrared and is the world’s largest survey telescope and the VLT Survey Telescope is the largest telescope designed to exclusively survey the skies in visible light. ESO is the European partner of a revolutionary astronomical telescope ALMA, the largest astronomical project in existence. ESO is currently planning the 39-metre European Extremely Large optical/near-infrared Telescope, the E-ELT, which will become “the world’s biggest eye on the sky”.

mardi 8 avril 2014

Image above: This image from NASA's Curiosity Mars rover, taken on April 3, 2014, includes a bright spot near the upper left corner. Possible explanations include a glint from a rock or a cosmic-ray hit. Image Credit: NASA/JPL-Caltech.

Images taken by NASA's Curiosity Mars rover on April 2 and April 3 include bright spots, which might be due to the sun glinting off a rock or cosmic rays striking the camera's detector.

The rover took the image just after arriving at a waypoint called "the Kimberley." The bright spot appears on a horizon, in the same west-northwest direction from the rover as the afternoon sun.

"In the thousands of images we've received from Curiosity, we see ones with bright spots nearly every week," said Justin Maki of NASA's Jet Propulsion Laboratory, Pasadena, Calif., leader of the team that built and operates the Navigation Camera. "These can be caused by cosmic-ray hits or sunlight glinting from rock surfaces, as the most likely explanations."

If the bright spots in the April 2 and April 3 images are from a glinting rock, the directions of the spots from the rover suggest the rock could be on a ridge about 175 yards (160 meters) from the rover's April 3 location.

The bright spots appear in images from the right-eye camera of the stereo Navcam, but not in images taken within one second of those by the left-eye camera. Maki said, "Normally we can quickly identify the likely source of a bright spot in an image based on whether or not it occurs in both images of a stereo pair. In this case, it's not as straightforward because of a blocked view from the second camera on the first day."

At the Kimberley and, later, at outcrops on the slope of Mount Sharp inside Gale Crater, researchers plan to use Curiosity's science instruments to learn more about habitable past conditions and environmental changes.

NASA's Jet Propulsion Laboratory, a division of Caltech in Pasadena, manages the Mars Science Laboratory Project for NASA's Science Mission Directorate, Washington. The project designed and built the project's Curiosity rover and operates it on Mars.

When people in North America look up at the sky in the early morning hours of April 15, they can expect the moon to look a little different.

A total lunar eclipse is expected at this time, a phenomenon that occurs when the Earth, moon and sun are in perfect alignment, blanketing the moon in the Earth's shadow.

Although lunar eclipses happen multiple times in a year during a full moon, this eclipse will be a particularly unusual viewing opportunity for North America. Since the Earth's Western Hemisphere will be facing the moon during the eclipse, the continent will be in prime position to view it from start to finish. In addition, the eclipse will coincide with nighttime in North America. The entire continent won't be able to witness a full lunar eclipse in its entirety again until 2019.

"Sometimes they'll happen and you'll have to be somewhere else on Earth to see them," said Noah Petro, Lunar Reconnaissance Orbiter deputy project scientist at NASA's Goddard Space Flight Center in Greenbelt, Md. "Most [residents] of the continental United States will be able to see the whole thing."

For those who are awake to watch the eclipse, which is scheduled to begin around 2:00 a.m. EDT and last over three hours, Petro said there would be several changes people can witness. When the moon first enters the Earth's partial shadow, know as the penumbra, a dark shadow will begin creeping across the moon. This will give the illusion that the moon is changing phases in a matter of minutes instead of weeks.

"Eventually there will be a chunk of darkness eating the moon," Petro said.

Understanding Lunar Eclipses

Video above: It's not often that we get a chance to see our planet's shadow, but a lunar eclipse gives us a fleeting glimpse. During these rare events, the full Moon rapidly darkens and then glows red. Though a lunar eclipse can be seen only at night, it's worth staying up to catch the show. Image Credit: NASA's Goddard Space Flight Center.

At the eclipse's peak, around 3:45 a.m. EDT, the moon will enter the Earth's full shadow, the umbra. At this stage, the Earth's atmosphere will scatter the sun's red visible light, the same process that turns the sky red at sunset. As a result, the red light will reflect off the moon's surface, casting a reddish rust hue over it.

"It's a projection of all the Earth's sunsets and sunrises onto the moon," Petro said. "It's a very subtle effect, and if any part of the moon is illuminated in the sun, you can't really see it."

Although lunar eclipses are fairly common, Petro said they don't happen every month. Because the moon's orbit is tilted, it doesn't pass through the Earth's shadow each time it orbits the planet. This is the same reason why solar eclipses—which occur when the Earth passes through the moon's shadow—don't occur monthly.

Petro said lunar eclipses are a special treat people should take the opportunity to watch, even if it is at a late hour.

"They don't happen all the time, and the sky has to be clear," Petro said. "It really gives you a chance to look at the moon changing."

In addition to being a spectacle for North America residents, Petro said NASA's Lunar Reconnaissance Orbiter (LRO) team would be paying particular attention to this eclipse. The LRO mission, which is currently orbiting the moon, will be plunged into darkness for an extended period during the eclipse. Because the spacecraft's batteries need sunlight to charge, it will be forced to run without recharging longer than usual.

Image above: Artist concept of the Lunar Reconnaissance Orbiter with Apollo mission imagery of the moon in the background. Image Credit: NASA.

"The spacecraft will be going straight from the moon's shadow to the Earth's shadow while it orbits during the eclipse," Petro said.

While this isn't the first time LRO has orbited the moon during an eclipse, its past orbits have allowed it to pass into Earth's shadow only for a short period. This time, the spacecraft will have to pass through the complete shadow twice before the eclipse ends. However, Petro said the team expects the spacecraft to make it through the eclipse without a hitch.

"We're taking precautions to make sure everything is fine," Petro said. "We're turning off the instruments and will monitor the spacecraft every few hours when it's visible from Earth."

Although LRO would be forced to shut down its instruments for this eclipse, Petro said other lunar eclipses are a great opportunity for the mission to study how the lunar surface cools during these events, giving insight into the materials making up the surface.

While people watch the moon change in the sky April 15, the LRO team will be ready.

"For quite a while, people in LRO have been analyzing what's going to happen during this eclipse," Petro said. "We'll make sure the world knows LRO survived with no problems."

Two days after launch, the first Sentinel satellite for Europe’s Copernicus programme has passed its initial instrument checks and technical verifications of the ground segment.

Early on Sunday morning, the C-band synthetic aperture radar was switched on for a few minutes under the command of the Svalbard ground station in Norway.

Sentinel-1 radar modes

The first data were then transmitted to southern Italy’s Matera ground station, before being automatically sent to the processing and archiving centre in Farnborough, United Kingdom, both part of the Copernicus Space Component ground segment.

The switch-on operation – part of the Launch and Early Orbit Phase, or LEOP – provided an early indication that the on-board radar is working nominally. It also demonstrated that the full chain of the instrument, from commanding to the generation of the final data by the ground segment, is functioning well.

“I am very proud of these initial results of the Sentinel-1 mission and would like to congratulate all teams for the excellent work carried out so far on the mission and in particular in the LEOP phase,” said Volker Liebig, Director of ESA’s Earth Observation Programmes.

For this initial test, the radar was operated in ‘wave mode’, which acquires data over 20 x 20 km areas alternately on two different incidence angles every 100 km. Once the satellite is operational, this mode will be used to determine the direction, length and heights of waves on the open oceans.

Sentinel-1’s radar

With LEOP completed by Sunday evening, the mission has now entered the three-month commissioning phase, during which all tests to prepare for the routine operational phase are performed. The radar will be turned on to begin regular acquisitions on 10 April.

ESA and the European Commission plan to release of a first set of radar images next week. A press event on the initial results of the mission is scheduled for early May, and will be organised jointly by ESA and the Commission.

The advanced radar instrument can ‘see’ through clouds and in the dark, providing an all-weather, day-and-night supply of imagery of Earth’s surface.

These data will be used to benefit numerous services for Europe’s Copernicus environmental-monitoring programme. These services include the monitoring of Arctic sea-ice extent, routine sea-ice mapping, surveillance of the marine environment, including oil-spill monitoring and ship detection for maritime security, monitoring land surface for motion risks, mapping for forest, water and soil management, and mapping to support humanitarian aid and crisis situations.

Sentinel-1 is designed as a constellation of two identical satellites, Sentinel-1A and -1B, that will orbit Earth 180° apart. Sentinel-1A was launched on 3 April from Europe's Spaceport in French Guiana.

Rocket Soyuz-U with THC Progress M-22M was launched from the Baikonur Cosmodrome February 5, 2014 at 20 hours 23 minutes 32 seconds Moscow time. February 6, 2014 2 hours and 22 minutes Moscow time docking of cargo spacecraft Progress M-22M from the International Space Station. Docked to the docking bay, Pierce was held in the automatic mode.

Cargo spacecraft delivered to the ISS more than 2.5 tonnes of goods: fuel, food, send the crew, photo and video equipment, water and other consumable materials necessary for the operation of the station in manned mode.

The moons of our Solar System are brimming with unusual landscapes. However, sometimes they look a little more familiar, as in this new radar image from the Cassini orbiter. The image shows dark streaks carved into dunes reminiscent of those we might find on a beach on Earth, or raked with flowing lines in a Japanese Zen garden — but this scene is actually taking place on Saturn’s moon Titan.

While our sand is composed of silicates, the ‘sand’ of these alien dunes is formed from grains of organic materials about the same size as particles of our beach sand. The small size and smoothness of these grains means that the flowing lines carved into the dunes show up as dark to the human eye.

These grains are shunted around by winds shifting over the moon’s surface. These winds aren’t particularly fast — only moving at around 1 m/s — but they blow in opposing directions throughout the year, causing Titan’s ‘sand’ to pile up in certain places over time.

Artist's view of Cassini-Huygens Titan fly-by

Titan seems to be full of features and phenomena that are quite familiar to those found on Earth. Since Cassini arrived in the Saturn system in 2004, and dropped off ESA’s Huygens probe in 2005, scientists have been studying the similarities between Titan and Earth by exploring sand dunes, channels and lakes of liquid ethane and methane scattered across its surface.

While previous images have spotted these eerily familiar patterns on Titan’s dunes, this new image shows them in greater detail. The image was obtained by Cassini’s Titan radar mapper on 10 July 2013, by a team led by Steve Wall at NASA’s Jet Propulsion Laboratory in California, USA. The horizontal seam near the centre is an artifact of radar image data processing.

The Cassini–Huygens mission is a cooperative project of NASA, ESA and Italy's ASI space agency.